This is due to the presence of material variations within the Earth which affect the speed with which the waves travel (specifically the density and elastic moduli of the material). When the wave crosses the boundary between two differing materials at any other angle than 90 degrees, the path that the wave travels will alter. This process is known as refraction.
The earth is highly heterogeneous. This means that it's properties are very variable in all directions. However there are some broad trends. This includes a trend of increasing density with depth. As increases in density cause increases in the velocity of seismic waves, this also causes refraction to occur altering the direction the wave travels. As this variation is gradual the change in the path of the wave is gradual and so ultimately the wave follows a curved path made up of lots of small changes in it's direction of travel as the density and other properties vary.
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For P waves, the two descriptive words are Primary (or compressional) waves, while for S waves, the two words are Secondary (or shear) waves.
Secondary waves, also known as S-waves, are seismic waves that arrive after primary waves (P-waves) during an earthquake. They are slower than P-waves and travel through the Earth by causing particles to move in a perpendicular motion to the direction of wave propagation.
There are three types of vibrations:- Primary waves, Secondary waves and long waves. Primary waves can move through solid and liquid. Secondary waves move through only solids and long waves can only move along the surface of the earth's crust.
Surface waves typically cause more damage than primary or secondary waves during an earthquake. They travel along the earth's surface and are responsible for the shaking that can result in building collapse and other structural damage. Primary and secondary waves, while important for seismologists to study, usually do not cause as much damage as surface waves.
As the distance traveled by the primary and secondary waves increases, the time difference between them also increases. This is because primary waves travel faster through the Earth than secondary waves, resulting in a greater time gap between their arrivals at a given location.
Primary seismic waves travel the fastest.
Secondary waves.
Primary waves, Secondary waves, and Seismic waves
Primary Waves, Secondary Waves, and Surface Waves.
P waves (primary waves) and S waves (secondary waves).
Seismic waves Types: Primary waves Secondary waves Surface waves
Primary and secondary refer to the order in which they come out, surface waves are called surface because they resonate close to the surface
For P waves, the two descriptive words are Primary (or compressional) waves, while for S waves, the two words are Secondary (or shear) waves.
The three types of earthquake waves are primary waves, surface waves, and secondary waves.
how far away you are from the focus of an earthquake
P or primary wave, S or secondary waves, L as in something waves
P or primary wave, S or secondary waves, L as in something waves